Bathtub



FIG. 1 is a top front perspective view of a bathtub showing our design;

FIG. 2 is a top plan view thereof; and,

FIG. 3 is a front elevational view thereof.

The broken line representation of opening in FIGS. 1 and 2 are forpurposes of illustration only and form no part of the claimed design.

The ornamental design for a bathtub, as shown and described.